This invention relates to surgical instruments and, in particular, to a powered instrument for attaching and removing a clip on a blood vessel during a surgical operation.
In various surgical operations, it is often necessary to temporarily close blood vessels to prevent loss of blood and to prevent the surgeon's view from becoming obscured by blood. In some procedures, a hemostat (a forceps-like instrument) is used to press together opposite sides of a blood vessel to block the flow of blood. The hemostat has a latch mechanism on its handles for keeping the jaws of the hemostat closed upon the blood vessel until the latch is released by the surgeon. For deep incisions, there is often not enough room for one or more hemostats to be left in place while the procedure continues. In this situation, spring loaded clamps, known as aneurism clips, are used which are much smaller than a hemostat and interfere much less with the surgeon. The clips are attached and released with a separate instrument known as an applier.
Aneurism clips are well known in the art and are commercially available in over one hundred sizes and shapes to meet every possible circumstance which a surgeon may encounter. The problem is getting the clip to the attachment site properly oriented with respect to the vein or artery. A second, but no less significant problem, is to apply the clip with an instrument which does not obscure the surgeon's view of the site or of adjacent, delicate tissue.
Minimally invasive surgical procedures, i.e. procedures using the smallest and fewest incisions possible, were originally used for surgery in and around the brain. Later, arthroscopic surgery was developed. Now, minimally invasive procedures are being developed for all areas of the body, e.g. abdominal and thoracic surgery. Any minimally invasive procedure greatly increases the skill required of the surgeon since the exposure of the patient is small. When a small incision is combined with a deep exposure, e.g. 100 mm, visualization and application can become quite difficult.
At rest, a clip is held closed by a spring which is an integral part of the clip. For insertion, the clip is placed in the jaws of the applier and is opened by closing the jaws of the applier. Clip appliers of the prior art are typically articulated or hinged at a point near one end, i.e. the jaws are much shorter than the handles. Since the jaws of the applier are closed, the handles of the applier are relatively close to each other. In this position, the applier is as narrow as it can be.
Positioning the clip can be difficult if it is necessary to insert the applier in a direction other than perpendicular to the surface of the body. Even though the jaws are closed, the width of the applier limits its insertion angle, i.e. the angle from perpendicular. In addition, the surgeon must rotate his hand to orient the clip properly with respect to the blood vessel. Often, this obliges the surgeon to operate the applier at an awkward hand position.
Opening the jaws of the applier to attach the clip, or to retrieve the clip, can be quite difficult because this widens the applier. Since the hinge is near one end of the applier, the handles must be opened a considerably greater distance than the jaws open. It becomes progressively more difficult to operate the applier at greater depths. The applier can obscure the surgeon's view of the clip and the blood vessel, particularly at the critical moment of attachment or removal. Both jaws move in commercially available appliers, requiring a clear view of both jaws and the region around them. In addition, the surgeon must manually actuate the applier without letting the hand motion cause any other movement of the applier. The result is a time consuming, delicate process which prolongs the surgery and is very demanding of the surgeon.
U.S. Pat. No. 3,613,683 discloses a clip applier using a pair of parallel bars sliding one on the other, actuated by the gripping action of the surgeon's hand. One end of the fixed bar is in the shape of a hook for receiving a clip, which is held between the ends of the two bars. While providing a somewhat narrower instrument, it requires the surgeon to rotate his hand to orient the clip and to manually operate the instrument.
U.S Pat. No. 4,038,987 discloses a forceps used as a clip applier having jaws operated by a toggle joint connected by wire to a syringe-like actuator. As with other appliers in the prior art, the surgeon must rotate his hand to orient the clip and manually operate the instrument.
In view of the foregoing, it is therefore an object of the invention to provide a powered, remotely controlled, surgical instrument for operating a jaw mechanism at any desired rotational orientation relative to the hand of a surgeon.
A further object of the invention is to provide an aneurism clip applier which can be oriented prior to insertion.
Another object of the invention is to provide an aneurism clip applier which requires no separate hand movement for attaching or removing clips from blood vessels.
A further object of the invention is to provide a surgical instrument capable of greater insertion angle than prior art instruments.
Another object of the invention is to provide an aneurism clip applier enabling improved visualization and application.